The Giants on Tuesday allowed the three-time Pro Bowl safety Landon Collins to enter free agency rather than use an $11.15 million franchise tag that would have kept him a Giant.

It was startling decision because Collins, 25, was one of the few stars on a porous defense that even the Giants’ brain trust blamed for a dispiriting 5-11 record last season.

But more alarming is that Collins’s departure continues a discouraging trend in recent Giants history: the procession of top draft picks discarded by the team.

Collins was a second-round selection in 2015. The Giants traded three picks (in the second, fourth and seventh rounds) to move up so they could take Collins with the first choice of the second round.

Now Collins, in the early part of his prime, is unencumbered in free agency, where he will draw considerable interest. It’s a familiar fate for a Giants draft pick.

In 10 drafts from 2008 to 2017, the Giants selected 70 players. Only seven are still with the team.

The player the Giants chose in the first round ahead of Collins in 2015, tackle Ereck Flowers, was a colossal bust and was cut from the team early last season. In fact, no other player from the Giants 2015 draft class is still on the roster.

That is hardly an aberration. The only player left from the 2014 draft class is Odell Beckham Jr. No player selected in 2013 is still with the team, and only two from 2016 are in a Giants uniform.

The Giants’ approach to team building — if that’s even an appropriate term since they have had just one winning season since 2012 — has been highly unconventional as compared with their peers. In an era of salary cap restrictions, most N.F.L. teams have treated their draft selections like prized jewels to be coveted as they molded rosters with carefully chosen picks from the amateur draft.

Collins certainly appeared to be the one selection of the Giants’ 2015 draft who would make the team proud for many seasons. After an uneven rookie season, a typical outcome for a first-year defensive back, Collins had five interceptions and 100 solo tackles in his second season, resulting in his being named to the All-Pro team.

Collins’s production slumped slightly in the next season when he was not 100 percent because of injury. The same was true in 2018, but Collins still made the Pro Bowl in each of the last two seasons. He led the team in tackles in each of his four seasons.

Collins also grew into a respected team leader who was a dependable, stand-up presence in an often fractious locker room that endured two coaching changes and consistent losing.

It is true that Collins’s strengths as a player are as a run stopper, and last season his lack of downfield coverage skills were occasionally laid bare by opponents. Every year, the N.F.L. becomes more of a pass-first league, and it’s possible that the Giants will seem prescient for not investing heavily in a safety who might not be as valuable in a few years when teams are throwing the football 70 percent of the time — or more often.

And then, of course, there is considerable salary that Collins would have commanded under the Giants’ franchise tag. More than $11 million is a lot for a safety. But the Giants could have negotiated a long-term contract with Collins to mitigate the annual cost.

Meanwhile, it’s hard to forget that Eli Manning, who is 38 and has won eight games as the Giants’ starting quarterback in the last two seasons, will count $23.2 million against the Giants’ salary cap in 2019.

The overarching strategy of Giants General Manager Dave Gettleman, who has been charged with fixing most of the draft choice blunders made by his predecessor, Jerry Reese, is not clear. Gettleman may be counting on the Giants receiving a high-round compensatory draft pick when Collins signs with another team. In addition, Gettleman may have feared that Collins, if designated with the franchise tag, would stay away from the team throughout training camp this summer, a negotiating tactic employed in recent years by other players seeking long-term deals. The Giants may not have wanted that distraction.

What is known is that a poor Giants defense just got substantially worse. The Giants will now have more money to pursue free agents to resolve that expanding deficiency. And, bucking a trend, they had better draft wisely.

A version of this article appears in print on , Section B, Page 10 of the New York edition with the headline: Giants Let Another High Draft Choice Go. Order Reprints | Today’s Paper | Subscribe